This invention is related to a fluid controller, and its object is to provide the fluid controller that is superior in processability, whereof branch plumbing is easy and puddle never occurs in flow paths.
As a fluid controller used as usual, one with the structure shown in FIG. 22 is exemplified.
The fluid controller in FIG. 22 comprises a valve body C having an inlet flow path A and an outlet flow path B, a diaphragm D, a bonnet E holding fixedly periphery part of the diaphragm and an operation mechanism G moving the diaphragm in vertical direction, wherein the diaphragm D is contacted and separated to a valve base F by operating operation mechanism G so that the inlet flow path A and the outlet flow path B becomes closure state or communication state.
In the conventional fluid controller as shown in FIG. 22, however, the center processing for a cave, i.e. the inlet flow path A, the outlet flow path B and the valve body C must be accurate well adjusted when processing the flow paths so that processability was very poor because the valve base F is provided as a protrusion between the inlet flow path A and the outlet flow path B are curved and are opened at the surface of valve body C.
Also, there is a problem whereof the puddle of fluid is easy to occur inside the plumbing because flow paths are curved at the portion of the valve base F.
Moreover, in case of using this fluid controller with carrying out welding and the like as a branch valve, the processability is very poor because disposal to lean a body to the diagonal direction and so on is required.
For prior art invented in order to solve said problem, there is the invention disclosed in Japan tokukaihei 1-320378, for example.
The invention disclosed in Japan tokukaihei 1-320378 comprises that an inlet flow path and an outlet flow path which are arranged on the identical axis line, these inlet flow path and outlet flow path are connected with a communication path where it has no protrusion, wherein a diaphragm is contacted and separated to the inside under the communication path.
Since the inlet flow path and the outlet flow path which are arranged on the identical axis line are connected with the communication path where it has no protrusion, this invention disclosed is superior in the processability of the flow path compared with a conventional fluid controller and moreover puddle of fluid inside of the plumbing is hard to occur because there is no curve on flow paths. However, when adjusting to correspondence for the center of the diaphragm and a center of width direction of communication flow path is not carried out accurately, the flow path could not be surely closed down so that the accurate adjusting work was required.
On the other hand, for plumbing such as a pipeline system, a T-letter shaped fluid controller showing in plan view having a main path and the branch path at right angles to this main path is often used with connecting the plumbing in order to sample fluid.
In the fluid controller having a conventional branch path, however, when using the branch path substantially horizontally and the main path downward, the puddle is occurred at the bump and it becomes the cause such as propagation of the miscellaneous germs since bump exists on communication surface from the branch path to the seal base, so it is not preferable.
For prior art invented in order to solve said problem, there is the invention disclosed in Japan Patent No.2591876 (PCT/GB91/01025).
The invention disclosed in Japan Patent No.2591876 (PCT/GB91/01025) comprises a T-letter shaped fluid controller showing in plan view, wherein communication surface from the branch path to the seal base becomes horizontal or inclined to the main path when directing the branch path substantially horizontally and the main path downward
By the above invention, an occurrence of the puddle by the bump was prevented since there is no bump which used to exist; however, the processability is very bad and it is difficult to disappear bump completely.
This invention is for solving the above problem, and tries to provide the fluid controller which can achieve both prevention of occurrence of puddle in the flow path and good processability.
The invention relates to a fluid controller comprising: a valve body having flow paths used as inlet and outlet for fluid: a diaphragm held fixedly between the valve body and a bonnet; and an operation mechanism moving the diaphragm in vertical direction, wherein said flow paths of the valve body communicate with each other through a protrusion-free communication path, said diaphragm is fitted closely to the communication path when lowered so as to close the flow path and when raised, the center part of the diaphragm is recessed and its part near the outer periphery part is protruded, and a curved surface to which an outer surface of said protruded part is closely fitted is formed on said bonnet at the inner lower surface of a diaphragm holding part.
The invention relates to a fluid controller wherein said flow paths provided on the valve body are comprised an inlet flow path and an outlet flow path which are arranged on the identical axis line.
The invention relates to a fluid controller wherein said flow path provided on a valve body is a T-letter shaped flow path comprising a penetration flow path penetrating the valve body and a branch flow path branched from the penetration flow path and a bottom surface of the penetration flow path exists at the same level as a bottom surface of the communication path.
The invention relates to a fluid controller wherein said flow path provided on a valve body is a T-letter shaped flow path comprising a penetration flow path penetrating the valve body and a branch flow path branched from the penetration flow path, the penetration flow path is where a central axis line thereof is positioned below a bottom of said communication path, and a communication surface from the penetration flow path to the communication path is formed as an inclination horizontally or downward when the penetration flow path is arranged horizontally and the branch flow path is arranged downward.
The invention relates to a fluid controller wherein the diameter of said penetration flow path is larger than the diameter of the branch flow path.